import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;

public class demo21 {
    public static void main(String[] args) {
        try (FileWriter fileWriter = new FileWriter("output.txt", true)) {
            fileWriter.write(97);
            fileWriter.write(98);
            fileWriter.write("aaa");
        } catch (IOException e) {
            throw new RuntimeException(e);
        }

    }
}
